Antipsych Meds

Anti-Psychotics (A-P) Overview

  • Classification of Anti-Psychotics: 3 Generations: 1st, 2nd, and 3rd.

First Generation Anti-Psychotics (FGAs)

  • Definition: Traditional dopamine D2 antagonists affecting both limbic and motor areas.

  • Mechanism: Blockade of dopamine in motor areas can result in extrapyramidal side effects (EPS).

  • Common Names: Also known as conventional antipsychotics or neuroleptics.

  • Effectiveness: Primarily alleviate positive symptoms of schizophrenia, including:

    • Hallucinations

    • Delusions

    • Disordered thinking

  • Side Effects (S/E): Include sedation and EPS, characterized by:

    • Muscle stiffness

    • Gait disturbances (often described as "walking like a robot")

Second Generation Anti-Psychotics (SGAs)

  • Definition: Serotonin-dopamine antagonists, also referred to as atypical antipsychotics.

  • Mechanism: Improve both positive and negative symptoms of schizophrenia.

  • Side Effects: Metabolic Syndrome includes:

    • Weight gain

    • Dyslipidemia

    • Altered glucose metabolism

    • Increased risk of diabetes

    • Increased hypertension and atherosclerotic heart disease.

Third Generation Anti-Psychotics

  • Example: Aripiprazole (Abilify)

General Characteristics

  • Onset of Effects: All antipsychotic medications require 2-6 weeks for effects to stabilize, often needing dosage adjustments for optimal outcomes.

  • Elderly Patients: Increased mortality risk in elderly patients with dementia using A-P medications.

  • Addiction: None of the A-Ps are addictive, but rebound effects can arise, briefly amplifying psychotic symptoms after cessation.

Pharmacological Interventions

  • Augmentation Strategy: Anticonvulsants are utilized alongside A-Ps approximately 30% of the time.

Extrapyramidal Symptoms (EPS)

  • Definition: Serious movement disorders due to strong dopamine blockade in the CNS by FGAs.

  • Comparison with SGAs: SGAs moderately block dopamine receptors and strongly block serotonin receptors, resulting in a lower risk of EPS.

  • Implications of SGA Use: Carry a greater risk of metabolic side effects, including weight gain, diabetes, and dyslipidemia leading to cardiovascular complications.

  • Efficacy: Antipsychotics effectively suppress symptoms during acute phases and reduce relapse risk with chronic usage.

    • Initial effects may be observed within 1-2 days, but significant improvement often requires 2-4 weeks, and full efficacy may take several months to develop.

Adverse Effects of FGAs

  • Focus on EPS: The adverse effects of FGAs, particularly EPS, are a significant concern, leading to their classification as neuroleptics.

Types of EPS Disorders

  1. Acute Dystonia

    • Onset: Occurs within days to hours after therapy initiation.

    • Symptoms: Severe muscle spasms in areas such as the tongue, face, neck, and back; potential for oculogyric crisis (involuntary eye movement).

    • Treatment: Anticholinergic medications (e.g., benzotropine (Cogentin), diphenhydramine) via IM or IV; rapid intervention is crucial.

  2. Parkinsonism

    • Symptoms: Bradykinesia, mask-like expressions, drooling, rigidity, tremors, shuffling gait, stooped posture.

    • Onset: Within the first month of therapy; indistinguishable from Parkinson's disease.

    • Treatment: Anticholinergic agents (e.g., benzotropine, amantadine) or switch to SGA for severe symptoms.

  3. Akathisia

    • Symptoms: Uncontrollable urge to be in motion, pacing, and restlessness.

    • Onset: Usually develops within the first two months; less common in SGAs.

    • Treatment: Beta blockers, benzodiazepines, and anticholinergics.

  4. Tardive Dyskinesia (TD)

    • Prevalence: Affects 15-20% of long-term therapy patients.

    • Symptoms: Involuntary choreoathetoid movements (twisting, writhing), lip-smacking, and disrupted chewing/swallowing.

    • Intervention: Withdrawal of FGAs, administration of benzodiazepines, and switching to SGAs. Close monitoring required due to lack of known treatment for TD.

Neuroleptic Malignant Syndrome (NMS)

  • Prevalence: Rare but severe, with a 10% mortality risk.

  • Symptoms: "Lead pipe" rigidity, sudden high fever (exceeding 41°C), autonomic instability, altered LOC.

  • Management:

    • Supportive care, immediate withdrawal of A-P meds.

    • Management of hyperthermia with cooling measures.

    • Hydration, benzodiazepines for anxiety and autonomic stability.

    • Medications such as dantrolene (muscle relaxant) and bromocriptine (dopamine agonist) to address CNS toxicity.

Anticholinergic Toxicity

  • Effects of FGAs: Variable anticholinergic responses, including:

    • Dry mouth, blurred vision, urinary hesitancy, constipation, tachycardia.

    • Severe symptoms may lead to a life-threatening medical emergency.

Other Side Effects of FGAs

  • Weight gain

  • Sexual dysfunction

  • Endocrine disturbances (e.g., galactorrhea, amenorrhea, gynecomastia)

  • Drooling

  • Tardive Dyskinesia (TD)

Additional Concepts and Definitions

  • Akinesia: Absence of movement or lack of reaction in a motor capacity.

  • Kinesia: Suffix meaning movement.

  • Bradykinesia: Slowness of voluntary movements and speech, prevalent in Parkinson's disease and EPS disorders; can also be induced by tranquilizers.